Paper lath



Patented Aug. 9, 1932 UNITED STATES PATENT OFFICE HERBERT E. MARKS, OF SEVICKLEY, PENNSYLVANIA, ASSIGNOR TO MARY HAINES MARKS, OF SEWICKLEY, PENNSYLVANIA :PAPER LATE Application filed February 13, 1931.

My invention pertains to paper lath and relates especially to paper lath of the characterv in which a backing of corrugated paper, or paper-like material, having metallic stiifening devices secured thereto is employed.

In building construction, it has become common to employ what is known as paperv -5 duce projections, at the rea-r of the backing,

which space the lath in a desirable manner from the studding or other support which is to carry the plaster. It is found in practice, however, that such corrugated paper backings tend to sag, and the corrugations thereof to straighten out, when the wet plaster is applied thereto. Various undesirable conditions result from this. For instance, when the lath is employed horizontally, the backing, and the whole body of plaster, is liable to sag downwardly. On the other hand, when the lath is employed vertically, the backing is liable to sag inwardly under the pressure of the trowel or other implement stead of flat.

' by means of which the plaster is applied, and

subsequently, after the plaster has been applied, to spring outwardly, the result being` that the surface of the plaster is waved in- Various means have been proposed from time to time to prevent collapse of the corrugations in such paper backings, and to stillen the whole backing against sagging. However, such constructions have been expensive and not entirely satisfactory in the results obtained.

Furthermore in the use of paper lat-h, in unit form, for the support of plaster or the like, it has been found that under certain circumstances cracks appear' along the lines where adjoining sections abut or overlap,

Serial No. 515,479.

owing probably, to the lessened rigidity of the backing, especially when moist, at these locations.

lt is the principal object of my invention to provide paper lath including a corrugatedq': paper backing which will beproofagainst collapse of the corrugations and sagging of the backing, and which will be of an exceptionally economical construction.

lt is a further object of my invention to ed provide paper lath of such character that when adjoining sections thereof are employed a ridge of plaster of increased thickness will be created along the lines of abutment or overlap the adjoining units, thereby pre- '65 venting the formations of cracks in the tin-l ished wall, ceiling or the like.

Gne form of paper lath embodying my invention is described in the following speciiication and shown in the accompanying drawing, in which: Y

Fig. l is a front view showing sections of paper lath embodying my invention as applied preparatory to the construction of wall;

Fig. 2 is an enlarged front View of a corner of a lath unit; and

Fig. 3 is a cross section, taken as on the line HI-III of Fig. 2, but showing two adjoining lath sections with the plaster or the like applied thereto. Referring now to the drawing, the section of paper lath shown therein comprises a backL ing sheet of paper l (which term is intended herein to include paper-like materials in general) in which are formed a series of spaced V-shaped corrugations 2. These co-rrugations run lengthwise of the backing sheet, which is ofan elongate rectangular form suitable to span a plurality of the studs 3 or 90 other` supports to which the plaster is to be applied, the V-shaped corrugations then running transversely of such studs. In certain of the corrugationsQ (in the instance shown in the top, bottom and middle corrugations) are disposed V-shaped metallic stilfening strips 4 which, in the particular embodiment shown, are of a shape corresponding with that ofthe corrugations 2 and arranged so that their edges are flush with the surface of the backing sheet 1, though such shape and arrangement may be varied. Spaced along the length of the backing sheet, at right angles to the corrugations 2, are sheet metal bridge members 5, of U shape in cross section. These members lie flat upon the backing sheet l and are secured to such backing sheet by means of staples G which are applied in the spaces between the corrugations 2.y The staples overle the bridge members and 'the operation of applying them causes indentations 5' Fig. 3) to be formed in the bridge members at the points where the staples cross the latter.

uch indentations prevent any transverse movement of the backing with respect to the brilgp members. l t

` en plaster is applied to the backing sheet, the latter becomes moistened, and, in the absence of means for preventing it, the backing sheet would be pushed back under the pressure of applying the plaster, thereby opening out the corrugations. However, by providing the bridge members and securing the latter to the backing sheet by staples disposed in the spaces between the corrugations, afs described above, the backing sheet is securely maintained against vany material lrearward movement under the pressure employed when applying the plaster.I Any appreciable flattening out of the eorru ations, there'- fore, is efectively prevented. n this connection, it will be noted that the backing sheet, under the tendency to be pushed rearward, Cannot slip transversely with respect to the bridge members, because of the fact that the staples are locked in the indentations bf the bridge members. The corrugations, therefdre, 'are maintained in shape by obviating the cause which would tend to distort them.

The longitudinal edges of the backing Iseo tiens are bent downward, as indicated at l", preferably to such an lextent that their 'margins laresubstantially level with the bottoms of the corru'gations. 'The bridge members are preferably likewise bent downward, afs indicated at 5a. The lat'h sections are applied to the studs 3, usually by nails V7 :driven through the longitudinal lstiii'ening members and into the studs. When fa second l'azth section is secured in place to the lstads with its edge abutting, yor slightly overlapping, the edge oit another lath section, fa channel-shaped depression, is formed, which, when the plaster'fS is applied, provides a ridge 8 'of plasteralong the line not juncture of the lath sections. Such ridge strengthens the plaster along 'the line 'where theI 'sections' Vjoln and eectively prevents the appearance of cracks along that line, the formation ofwhieh cracks has heretofore been a trouble frequently experienced in the use of pape-r lath sections `of the general character herein referred to.

Ielaim:

1. Paper lath comprising 'a paper backing sheet formed with longitudinal corrugations,

ported against lsu'eh movement with respect to the bridge members as would tend to distort said corrugations.

'2. A paper lath section comprising a paper backing sheet formed with longitudinal corrugations, stiffening ymembers in said corrugation's, individual bridge members extending transversely of kmid cor ione and ifeni members, and means or securing said rbri ymembers to saidibeeking sheet,

the longitudinal edges of said sheet being bent rearwardly, whereby a channel is created at the line of `juncture of two adjoining sections to provide a strengthening ridge of plaster at .such line.V

In testimony whereof, I sign In name` l HERBERT E. I ARKS.

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